Nimotuzumab combined with radiotherapy for esophageal cancer: preliminary study of a Phase II clinical trial

Efficacy and Safety of Concurrent Chemoradiotherapy Combined with Nimotuzumab in Elderly Patients with Esophageal Squamous Cell Carcinoma: A Prospective Real-world Pragmatic Study

BACKGROUND

Concurrent or definitive chemoradiotherapy is the standard treatment of locally advanced esophageal squamous cell carcinoma (ESCC). Elderly patients could not tolerate the standard concurrent chemotherapy and were treated with radiotherapy because of weak physical status and multiple comorbidities.

OBJECTIVE

The efficacy and safety profile of concurrent (chemo) radiotherapy combined with nimotuzumab in elderly patients with ESCC were investigated.

METHODS

Eligible elderly (≥70 years) patients with locally advanced ESCC were enrolled in this prospective, real-world pragmatic study and received concurrent chemoradiotherapy or radiotherapy combined with nimotuzumab. The primary endpoint was overall survival (OS). Secondary endpoints were objective response rate, disease control rate, progression-free survival (PFS), and adverse drug reactions.

RESULTS

Fifty-three elderly patients were enrolled. Thirty-two (60.4%) were treated with radiotherapy combined with nimotuzumab (RT+N), and 21 (39.6%) with concurrent chemoradiotherapy combined with nimotuzumab (CRT+N). The median age was 75.8 years. Fourteen (56.0%) patients achieved a partial response, and 11 (44.0%) patients achieved stable disease at 3 months. The median follow-up duration was 24.4 (95%CI, 21.6-26.7) months. Median OS (mOS) was 27.0 (95%CI, 14.8-48.4) months. Median PFS (mPFS) was 22.6 (95%CI, 12.4-not reached) months. Higher mPFS (not reached vs. 12.0 months; p=0.022) and mOS (48.4 vs. 15.3 months; p=0.009) were observed in the CRT+N group compared with the RT+N group. Most adverse reactions were grade 1-2 (46, 86.8%).

CONCLUSIONS

Concurrent chemoradiotherapy or radiotherapy combined with nimotuzumab was safe and well-tolerated in elderly patients with locally advanced ESCC. ESCC patients treated with CRT+N could live longer.

Nimotuzumab in the Treatment of Inoperable Esophageal Tumors of Epithelial Origin

Background

Nimotuzumab is a humanized monoclonal antibody that targets the epidermal growth factor receptor. It was approved in Cuba for the indication of inoperable malignant tumors of the esophagus of epithelial origin. The purpose of this study was to evaluate the safety, overall and progression-free survival, clinical response, and quality of life, in adult patients with inoperable esophageal tumors of epithelial origin treated with nimotuzumab in a practical context. Material and Methods. The number of patients who developed adverse events was determined, and the frequency, seriousness, causality, and severity of these adverse events were determined. It also determined the median of survival and progression-free survival and rates at 12 and 24 months and the quality of life.

Results

A total of 111 patients were included. The proportion of serious and related AE with the use of nimotuzumab was 1.3%. Most of the related AEs were mild and moderate, and the most frequent AEs were diarrhea, chills, and tremors. New diagnosed patients who received nimotuzumab concurrent with chemotherapy and radiotherapy reached a median OS of 12.2 months (95% CI, 6.9–17.5) and 12- and 24-month survival rates of 51.0% and 17.0%, respectively. Median PFS was 7.8 months (95% CI, 6.2–9.5), and 12- and 24-month PFS rates were 39.3% and 11.2%, respectively. A favorable evolution of the general state of health (p=0.03) was obtained from the beginning of treatment until month 12, with a significant reduction in the appearance of nausea (p=0.009), insomnia (p=0.04), constipation (p=0.04), eating difficulties (p=0.0006), and choking when swallowing (p=0.0001), but increased in dysphagia (p=0.02).

Conclusions

The administration of nimotuzumab was safe in the real-world setting. New diagnosed patients that received nimotuzumab concurrent with chemotherapy and radiotherapy reached a higher overall and progression-free survival and better quality of life than the rest of the patients. Trial registration is RPCEC00000215 (Cuban Registry of Clinical Trials; https://registroclinico.sld.cu/en/home). It is registered prospectively on June 30, 2016.

The Application of Nimotuzumab Combined With Definitive Chemoradiotherapy Toward the Treatment of Locally Advanced Cervical Esophageal Carcinoma: A Retrospective Study

Objective

To evaluate the safety and effectiveness of nimotuzumab in combination with chemoradiotherapy for locally advanced cervical esophageal squamous cell carcinoma.

Methods

Retrospective analysis was conducted from September 2012 to February 2017 among 50 locoregional-advanced cervical esophageal carcinoma (CEC) patients who received concurrent chemoradiotherapy (CRT) combined with or without nimotuzumab at Ningbo Medical Center Lihuili Hospital. Intensity-modulated radiotherapy (IMRT) was administrated on all patients. All patients were divided into two groups, of which 26 (Group A) received 200 mg (22 of 50) or 400 mg (4 of 50) of nimotuzumab per week with CRT and 24 (Group B) received definitive CRT.

Results

The median follow-up time was 23 months. The median overall survival (OS) and progression-free survival (PFS) were 40.6 and 21.1 months for all, respectively. The 1-, 2-, and 3-year OS rates on the whole were 79.6%, 62.1%, and 47.8%. There was no statistical difference in overall response rate and disease control rate between the two groups. Patients treated with nimotuzumab (group A) had better PFS than the definitive CRT group (group B) (P < 0.05). However, the median OS was 41.4 months in group A and 32.4 months in group B, respectively (P = 0.517). Multivariate analysis showed that PFS among those with lower Eastern Cooperative Oncology Group (ECOG) score (HR = 5.11; P < 0.01), stage II (HR = 9.52; P < 0.01) and the application of nimotuzumab combined with CRT (HR = 0.16; P < 0.01) was much longer. Furthermore, ECOG, stage, C-reactive protein (CRP) baseline, and histological grade can also be used as independent predictors of OS. Grade >3 adverse reactions were not observed. The most common adverse event related to nimotuzumab was mild fever and the occurrence rate was 19% (5 of 26). The incidence of anemia was 65.4% in group A and 87.5% in group B (P < 0.05).

Conclusions

For locoregional-advanced CEC, nimotuzumab combined with IMRT and concomitant chemotherapy was tolerated and effective. In addition, patients with a normal pretherapeutic serum CRP level (CRP < 10 mg/L) can achieve better OS.

Safety and efficacy of anti-EGFR monoclonal antibody (SCT200) as second-line therapy in advanced esophageal squamous cell carcinoma

OBJECTIVE

The mainstay treatment of esophageal squamous cell carcinoma (ESCC) involves chemotherapy and immunotherapy. However, alternative therapies are required for patients who are refractory or intolerant to existing therapies.

METHODS

In this single-arm, multicenter, open-label phase Ib study, 30 patients received an intravenous infusion of SCT200, an antiepidermal growth factor receptor (EGFR) monoclonal antibody, 6.0 mg/kg once a week for 6 weeks, followed by 8.0 mg/kg once every 2 weeks until disease progression or intolerable toxicity. The primary endpoint was the objective response rate (ORR). The secondary endpoints were progression-free survival (PFS), overall survival (OS), and safety.

RESULTS

Thirty patients were enrolled between July 2018 and May 2019. The ORR was 16.7% (95% CI: 5.6%-34.7%). The median PFS and OS were 3.1 months (95% CI: 1.5-4.3) and 6.8 months (95% CI: 4.7-10.1), respectively. A numerical difference without any statistical significance in ORR was observed in patients with different EGFR expressions (≥ 50%: 25.0% vs. < 50%: 0%, P = 0.140) or TP53 mutation abundance (< 10%: 23.8% vs. ≥ 10%: 0%, P = 0.286). Improved median PFS (3.4 vs. 1.4 months, P = 0.006) and OS (8.0 vs. 4.2 months, P = 0.027) were associated with TP53 mutation abundance of < 10%. The most common treatment-related adverse events of grade 3 or 4 (occurring in ≥ 2 patients) were hypomagnesemia [7 (23.3%)] and rash [2 (6.7%)]. No treatment-related death occurred.

CONCLUSIONS

SCT200 monotherapy as the second- or further-line treatment for advanced ESCC showed favorable efficacy, with an acceptable safety profile. TP53 mutation abundance might serve as a potential predictive biomarker.

Radiotherapy combined with nimotuzumab for elderly esophageal cancer patients: A phase II clinical trial

Objective

To investigate the safety and efficacy of nimotuzumab combined with radiotherapy for elderly patients with non-resectable esophageal carcinoma (EC).

Methods

Eligible patients were aged 70 years or older and had treatment-naïve, histologically proven inoperable locally advanced EC. Enrolled patients received radiotherapy with a total dose of 50−60 Gy in 25−30 fractions, concurrent with weekly infusion of nimotuzumab. The primary end point was the rate of more than grade 3 toxicities.

Results

From June 2011 to July 2016, 46 patients with stage II−IV EC with a median age of 76.5 years were enrolled. There were 10, 28 and 8 patients with stage II, III and IV disease, respectively. The common acute toxicities included esophagitis (grade 1−2, 75.4%; grade 3, 8.7%), pneumonitis (grade 1, 4.3%; grade 2, 6.5%; grade 3, 2.2%), leukopenia (grade 1−2, 60.9%; grade 3−4, 4.4%), gastrointestinal reaction (grade 1−2, 17.3%; grade 3, 2.2%), thrombocytopenia (grade 1−2, 21.7%; grade 3, 2.2%), and radiothermitis (grade 1−2, 39.2%). The incidence of grade 3−4 adverse effects was 17.4%. No grade 5 toxicities were observed. Clinical complete response, partial response, stable disease, and progressive disease were observed in 1 (2.2%), 31 (67.4%), 12 (26.1%), and 2 (4.3%) patients, respectively. The median overall survival (OS) and progression-free survival (PFS) were 17 and 10 months, respectively. The 2-, 3-, and 5-year OS and PFS rates were 30.4%, 21.7%, 19.6%, and 26.1%, 19.6%, 19.6%, respectively.

Conclusions

Nimotuzumab combined with radiotherapy is a safe and effective therapy for elderly patients who are not surgical candidates. Further studies are warranted to confirm its therapeutic effects in elderly EC patients.

Advances in the pharmacotherapeutic management of esophageal squamous cell carcinoma

INTRODUCTION

Esophageal squamous cancer remains an important cause of mortality worldwide with two new immunotherapy drugs recently approved for metastatic disease.

AREAS COVERED

The authors review the epidemiology and genomics of esophageal squamous cell carcinoma. They also examine prior trials involving targeted agents under investigation as well immunotherapies that have been approved and novel combinations.

EXPERT OPINION

Great advances have been made in characterizing the molecular changes in esophageal carcinoma. However, relatively few drugs have shown benefit in this disease. Targeted therapies have not shown to improve survival although many of these trials did not explore potential biomarkers. Pembrolizumab and nivolumab are now approved for esophageal squamous carcinoma but much more data are needed to understand how these agents may be used in non-metastatic settings. Novel treatments are still required as overall prognosis remains poor.

Icotinib With Concurrent Radiotherapy vs Radiotherapy Alone in Older Adults With Unresectable Esophageal Squamous Cell Carcinoma: A Phase II Randomized Clinical Trial

Importance

Palliative radiotherapy (RT) is generally recommended for older patients with esophageal squamous cell carcinoma (ESCC) with poor prognosis. A new combination treatment is therefore needed.

Objective

To assess the efficacy and toxicity of RT plus icotinib vs RT alone in older patients with ESCC.

Design, Setting, and Participants

This randomized, multicenter, open-label, phase II clinical trial was conducted in China, with enrollment between January 1, 2015, and October 31, 2016. Patients aged 70 years or older with clinical stage T2 to T4, N0/1, M0/1a unresectable (because of comorbidities, T4 disease, unresectable lymph node, or refused surgery) ESCC were randomized 1:1 to receive RT plus icotinib or RT alone. Radiation was prescribed at 60 Gy in 30 fractions in both groups, and icotinib was administered at a dosage of 125 mg 3 times a day in the RT plus icotinib group. The last follow-up was completed on June 30, 2019, and data were analyzed from July 1 to September 30, 2019.

Interventions

Patients were randomized to either RT plus icotinib or RT alone.

Main Outcomes and Measures

The primary end point was overall survival (OS). Treatment-related toxic effects were evaluated. Immunohistochemistry was performed to analyze epidermal growth factor receptor (EGFR) expression if available.

Results

A total of 127 patients (median age, 76 years [range, 70-91 years]; 76 men [59.8%]) were enrolled and were eligible for survival analysis. Median OS was 24.0 (95% CI, 22.2-25.8) months in the RT plus icotinib group vs 16.3 (95% CI, 13.8-18.8) months in the RT group (hazard ratio, 0.53; 95% CI, 0.33-0.87; P = .008). No difference was observed in grades 3 or 4 adverse events. Patients with EGFR overexpression had a significantly better median overall survival (not reached vs 16.3 months [range, 2.6-45.1 months]; P = .03) in the RT plus icotinib group.

Conclusions and Relevance

In this randomized clinical trial, icotinib plus RT was well tolerated and improved OS in older patients with ESCC relative to RT alone. Patients with EGFR overexpression benefitted more from icotinib with RT.

Trial Registration

ClinicalTrials.gov Identifier: NCT02375581.

Nimotuzumab Combined with Induction Chemotherapy and Concurrent Chemoradiotherapy in Unresectable Locally Advanced Hypopharyngeal Carcinoma: A Single Institution Experience in China

OBJECTIVE

To investigate the curative and adverse effects (AEs) of additional use of nimotuzumab combined with induction chemotherapy and concurrent chemoradiotherapy in unresectable locoregionally advanced hypopharyngeal carcinoma.

PATIENTS AND METHODS

We retrospectively evaluated 36 patients with stage III or IVA hypopharyngeal carcinoma who received induction chemotherapy followed by concurrent chemoradiotherapy with or without nimotuzumab. The induction chemotherapy included two or three cycles of TPF regimen. The intensity-modulated radiation therapy (IMRT) dose was 70 Gy to the planning target volume. Concurrent with radiotherapy, patients received chemotherapy consisting of cisplatin q3w. Adjuvant chemotherapy consisting of TPF regimen was administered 1 month later after concurrent chemoradiotherapy. Nimotuzumab (200 mg day 1, q3w) was given to patients concurrently with induction chemotherapy and was administered concurrently with IMRT at a weekly dose of 200 mg.

RESULTS

After induction chemotherapy, the objective response rate in patients treated with nimotuzumab (group A) versus those treated without nimotuzumab (group B) was 91.7% versus 58.3% (p=0.029). After concurrent chemoradiotherapy, the objective response rate was 95.8% in group A versus 83.3% in group B (p=0.253). The median follow-up was 22.6 months (range 8.9-39.5 months). The 2-year OS rate in group A and group B were 62.5% (95% CI 55-70%) and 51.8% (95% CI 45-59%), respectively, the 2-year OS rate in group A was better than group B, P<0.05. PFS was 23 months (95% CI 19-27) in group A versus 18 months (95% CI 12-22) in group B, PFS was longer in group A than group B, P<0.05. There was no significant difference in AEs between the two groups.

CONCLUSION

Additional use of nimotuzumab combined with induction chemotherapy and concurrent chemoradiotherapy in unresectable locoregionally advanced hypopharyngeal carcinoma yielded better short-term efficacy, also may improve overall survival and progression-free survival than patients without using nimotuzumab. The toxicity was tolerable.

A phase I study evaluating combined nimotuzumab and neoadjuvant chemoradiotherapy followed by surgery in locally advanced esophageal cancer

OBJECTIVE

The aim of this study was to evaluate the safety and efficacy of combined nimotuzumab and neoadjuvant chemoradiotherapy followed by surgery in locally advanced esophageal cancer.

METHODS

Patients with clinically resectable, locally advanced esophageal cancer treated with neoadjuvant chemoradiotherapy plus nimotuzumab were eligible for study participation. Radiotherapy was administered in 1.8 Gy once daily for 5 days per week up to a total dose of 41.4 Gy. Weekly nimotuzumab (200 mg/week) was administered following paclitaxel and carboplatin on the same day for 5 weeks. The primary end-point was the pathological complete response (pCR) rate and the secondary end-point was the safety, progression-free survival (PFS) and overall survival (OS).

RESULTS

A total of 64 patients with a median age of 58 years were enrolled in this study. pCR was observed in 51.6% patients. Grade 3 acute toxicities were observed in 6 patients (9.4%), shown as bone marrow suppression. 7 patients experienced grade 1 transient skin rash during nimotuzumab treatment. The median PFS time and OS time were 64.6 and 68.2 months.

CONCLUSIONS

Combined nimotuzumab and neoadjuvant chemoradiotherapy for clinically resectable, locally advanced esophageal cancer showed a significant anticancer effect with tolerable toxicities.

Effectiveness and tolerability of nimotuzumab in unresectable, locally advanced/metastatic esophageal cancer: Indian hospital-based retrospective evidence

Context:

Epidermal growth factor receptor (EGFR) is overly expressed in esophageal squamous cell carcinoma (ESCC) and is important prognostic and predictive biomarker. Nimotuzumab is a humanized anti-EGFR monoclonal antibody and has documented promising clinical outcomes and survival rates in various solid tumors with high EGFR expression.

Aims:

Attempt to fill gap on paucity of data in India on the efficacy of Nimotuzumab in the treatment of locally advanced/metastatic ESCC.

Settings and Design:

Hospital records of 15 patients with unresectable, locally advanced/metastatic esophageal cancers, histologically confirmed squamous cell carcinoma being treated with Nimotuzumab along with standard treatments from October 2006 to November 2016 were retrospectively analyzed.

Subjects and Methods:

The tumor response rate and overall survival (OS) were analyzed. All patients were assessed for toxicity and adverse events (AEs) as per Common Terminology Criteria for Adverse Events (CTCAE) v4.

Results:

Majority had lower thoracic esophageal cancer. Tumor response rate observed was as follows 33% had a complete response, 67% had a partial response, and objective response rate was 100%. Survival rate at 1-, 3-, and 5-year was 58.33%, 29.17%, and 29.17%, respectively. Median OS was 26.8 months (95% confidence interval, 2.63–not reached). No Grade III or Grade IV AEs were observed. No added toxicity was observed due to nimotuzumab.

Conclusions:

Nimotuzumab combined with standard treatment in locally advanced/metastatic ESCC improved the survival rate and achieved a better tumor response rate without accumulation of toxicity and was well tolerated.

Nimotuzumab Plus Paclitaxel and Cisplatin as a 1st-Line Treatment for Esophageal Cancer: Long Term Follow-up of a Phase II Study

The effect of anti-epidermal growth factor receptor targeted treatment in esophageal squamous cell carcinoma (ESCC) is still unclear. We conducted a prospective phase II study of paclitaxel, cisplatin, and nimotuzumab (TPN) as a first-line treatment for unresectable or metastatic ESCC and the objective response rate was 51.8%. Here, we report the long-term follow-up results of the initial trial. Fifty-nine patients were enrolled from Mar 2011 to Apr 2013 and were treated with the TPN regimen. Palliative sequential radiotherapy was given if all tumor lesions were confined to 1-2 radiation fields. Fifty-six patients were eligible for evaluation. After a median follow-up of 32.2months, the median progression-free survival (PFS) and the overall survival (OS) time were 18.1±4.2 months (95% CI: 9.8-26.4) and 26.2±10.0 months (95% CI: 6.6-45.8), respectively, in 29 patients with unresectable local-regional disease, while they were 6.6±0.4 months (95% CI: 5.8-7.5) and 11.5±3.7 months (95% CI: 4.2-18.8), respectively, in 27 patients with metastatic disease. Patients who were male, those with multiple station lymph node metastases, those with visceral metastasis, those who did not response to TPN treatment, and those who did not receive radiotherapy, had a worse OS. In 6 patients with multiple station lymph node metastasis and in 3 patients with recurrent disease and oligo-metastasis (local lymph nodes), TPN with sequential radiation resulted in a mean OS of 17.67±9.50 months and a mean OS of over 40 months, respectively. In conclusion, TPN is effective as a first-line treatment for patients with unresectable and metastatic ESCC. In addition, TPN treatment with sequential radiation might improve survival in patients with limited or oligo lymph node metastases.

Clinical Evaluation of Javanica Oil Emulsion Injection Combined with the Radiotherapy in the Treatment of Esophageal Cancer: A Systematic Review and Meta-Analysis

Objectives: This meta-analysis aimed to assess the clinical effectiveness and safety of Javanica oil emulsion injection (JOEI) combined with the radiotherapy (RT) for treating esophageal cancer (EC).

Design: A literature search was conducted for collecting the randomized controlled trials (RCTs) on EC treated by JOEI in the Cochrane Library, PubMed, Embase, the Chinese Biomedical Literature Database (SinoMed), the China National Knowledge Infrastructure Database, the China Science and Technology Journal Database (VIP), and the Wanfang Database from inception to February 4, 2017. The quality of the RCTs was evaluated by the Cochrane risk of bias assessment tool, and objective remission rate, performance status, adverse drug reactions (ADRs), 1-year survival rate, and 2-year survival rate were analyzed by Review Manager 5.3 and Stata 13.0 software.

Results: A total of 11 RCTs with 909 participants were involved in this meta-analysis. The results showed that in comparison with RT alone, the JOEI combined with RT was associated with the better effects on improving objective remission rate (relative risk [RR] = 1.33, 95% confidence interval [CI 1.17–1.52], Z = 4.44, p < 0.00001), performance status (RR = 1.52, 95% CI [1.25–1.85], Z = 4.24, p < 0.00001), 1-year survival rate (RR = 1.37, 95% CI [1.17–1.60], Z = 3.86, p < 0.0001), and 2-year survival rate (RR = 1.36, 95% CI [1.09–1.70], Z = 2.68, p = 0.007). The differences between the two groups in objective remission rate, performance status, 1-year survival rate, and 2-year survival rate were statistically significant. Besides, the JOEI combined with RT could reduce the incidence of ADRs. Specifically, the statistically significant difference was detected between these two groups about leukopenia (RR = 0.39, 95% CI [0.25–0.61], Z = 4.19, p < 0.0001), radiation esophagitis (RR = 0.68, 95% CI [0.50–0.93], Z = 2.42, p = 0.02), thrombocytopenia (RR = 0.92, 95% CI [0.12–0.66], Z = 2.95, p = 0.003), and hemoglobin reduction (RR = 0.53, 95% CI [0.35–0.79], Z = 3.14, p = 0.002); however, there was no statistically significant difference for the outcome of nausea and vomiting (RR = 0.61, 95% CI [0.36–1.03], Z = 1.85, p = 0.06) between two groups.

Conclusion: This meta-analysis indicated that the combination of JOEI and RT was associated with the more beneficial treatment for patients with EC compared with only receiving RT. However, more well-designed and multicenter RCTs should be carried out to confirm this finding because of the limitations of enrolled 11 RCTs.

Comparative study of dual energy CT iodine imaging and standardized concentrations before and after chemoradiotherapy for esophageal cancer

Background

To compare dual energy CT iodine imaging and standardized iodine concentration before and after chemoradiotherapy (CRT) for esophageal cancer and evaluate the efficacy of CRT for EC by examining DECT iodine maps and standard CT values.

Methods

The clinical data of 45 patients confirmed by pathology with newly diagnosed esophageal cancer who underwent concurrent CRT from February 2012 to January 2017 in our department of radiology were collected. All patients underwent dual-source dual-energy CT (DECT) before and after CRT. Normalized iodine concentration (NIC) and normalized CT (NCT) corresponding to the overall cancer lesion and its maximum cross-sectional area were observed and compared. Additionally, 30 healthy individuals were compared as control group. After treatment, the patients were divided into two groups according to RECIST1.1: treatment effective group and ineffective group.

Results

There were 33 patients (CR 9, PR 24) in the effective group and 12 patients (SD 12, PD 0) in the ineffective group. There was no significant difference in the NIC-A, NIC-V, NCT-A and NCT-A indexes between the effective group (B group) and the ineffective group (C group) before treatment (P > 0.05). After the treatment, the above-mentioned indexes in the effective group of patients were significantly lower than before treatment, and compared with the ineffective group, the NIC-A, NIC-V, NCT-A and NCT-V values of the effective group were significantly lower than those of ineffective group (P < 0.05). After treatment, the NIC-V and NCT-V in the ineffective group were lower than before treatment, and the difference was statistically significant (P < 0.05). However, their NIC-A and NCT-A were not statistically different from those before treatment (P > 0.05).

Conclusion

Using DECT iodine map, the changes of NIC and NIC before and after CRT in patients with esophageal cancer can evaluate the effect of CRT, and does not increase the radiation dose, so it is suitable for clinical use.

Enhancement of radiotherapeutic efficacy for esophageal cancer by paclitaxel-loaded red blood cell membrane nanoparticles modified by the recombinant protein anti-EGFR-iRGD

Paclitaxel is widely used as a radiosensitizer for various tumors, including esophageal cancer, but its therapeutic effect remains to be improved. In this study, we constructed a novel nano-radiosensitizer, anti-EGFR-iRGD-conjugated (iE)-PRNPs, by conjugating the recombinant protein anti-epidermal growth factor receptor (EGFR)-internalizing arginine-glycine-aspartic (iRGD) to the surface of paclitaxel-loaded red blood cell membrane nanoparticles (PRNPs). The iE-PRNPs were confirmed to possess tumor-targeting, high penetrability, and sustained release properties that free paclitaxel does not possess. Compared with that of paclitaxel, the sensitizer enhancement ratio of iE-PRNPs was significantly increased (1.32-fold and 1.25-fold) in esophageal cancer cells with high and low expression levels of EGFR, respectively. Additionally, compared with that of unmodified PRNPs, the sensitizer enhancement ratio of iE-PRNPs in EGFR-overexpressing esophageal cancer cells was significantly increased (1.27-fold), while that of PRNPs in esophageal cancer cells with a low EGFR expression level increased slightly (1.06-fold). The improved radiosensitization effect was associated with enhanced G2/M arrest, increased reactive oxygen species, and more effective induction of DNA double-strand breaks. In summary, iE-PRNPs appear to be a novel type of radiosensitizer with the potential to overcome the bottleneck of esophageal cancer radiotherapeutic efficacy.

Indoleamine 2,3-dioxygenase 1 and overall survival of patients diagnosed with esophageal cancer

BACKGROUND

Indoleamine 2,3-dioxygenase 1 (IDO1) is an enzyme with immunomodulatory properties that has emerged as a potential immunotherapeutic target in human cancer. However, the role, expression pattern, and relevance of IDO1 in esophageal cancer (EC) are poorly understood. Here, we utilize gene expression analysis of the cancer genome atlas (TCGA) and immunohistochemistry (IHC) to better understand the role and prognostic significance of IDO1 in EC.

RESULTS

High IDO1 mRNA levels were associated with worse overall survival (OS) in both esophageal squamous cell carcinoma (SCC) (P = 0.02) and adenocarcinoma (AC) (P = 0.036). High co-expression of IDO1 and programmed death ligand 1 (PD-L1) was associated with worse OS in SCC (P = 0.0031) and AC (P = 0.0186). IHC for IDO1 in SCC showed a significant correlation with PD-L1 (P < 0.0001) and CD3ε (P < 0.0001).

CONCLUSIONS

EC with high IDO1 and PD-L1 expression is significantly correlated with decreased patient survival, and may correlate with increased T-cells. These data suggest that simultaneous inhibition of IDO1 and PD-(L)1 may overcome important barriers to T-cell mediated immune rejection of EC.

MATERIALS AND METHODS

mRNA expression data from TCGA (SCC N = 87; AC N = 97). IHC in a second cohort of EC (N = 93) were stained for IDO1, PD-L1, and CD3ε, followed by light microscopic analysis.

Nimotuzumab combined with concurrent chemoradiotherapy in Japanese patients with esophageal cancer: A phase I study

Nimotuzumab is a humanized anti‐epidermal growth factor receptor IgG1 monoclonal antibody. This phase I study assessed the tolerability, safety, efficacy, and pharmacokinetics of nimotuzumab in combination with chemoradiotherapy in Japanese patients with esophageal cancer. Patients with stage II, III, and IV esophageal cancer were enrolled. Patients were planned to receive nimotuzumab (level 1: 200 mg/wk for 25 weeks; or level 2: 400 mg/wk in the chemoradiation period, 400 mg biweekly in an additional chemotherapy period [8 weeks after the chemoradiation period] and a maintenance therapy period [after chemotherapy to 25 weeks]) combined with cisplatin (75 mg/m² on day 1) and fluorouracil (1000 mg/m² on days 1‐4) in the chemoradiation and additional chemotherapy periods. Radiotherapy was given concurrently at 50.4 Gy. A total of 10 patients were enrolled in level 1. Dose‐limiting toxicities were observed in 2 patients (grade 3 infection and renal disorder). Maximum‐tolerated dose was estimated to be at least 200 mg/wk and the dose was not escalated to level 2. The most common grade ≥3 toxicities were lymphopenia (90%), leukopenia (60%), neutropenia (50%), and febrile neutropenia, decreased appetite, hyponatremia, and radiation esophagitis (30% each). Neither treatment‐related death nor grade ≥3 skin toxicity was observed in any patient. Complete response rate was 50%. Progression‐free survival was 13.9 months. One‐ and 3‐year survival rates were 75% and 37.5%, respectively. Immunogenicity was not reported in any patient. Nimotuzumab in combination with concurrent chemoradiotherapy was tolerable and effective for Japanese patients with esophageal cancer.

Association between glutathione S-transferase M1 polymorphism and esophageal cancer: a pooled analysis based on Chinese individuals

Many studies have analyzed the association between between glutathione S-transferase M1 (GSTM1) polymorphism and esophageal cancer, however, the results are inconsistent. This meta-analysis updated and reevaluated the possible associations between GSTM1 polymorphism and susceptibility to esophageal cancer based on Chinese individuals. The PubMed, Springer Link, Ovid, Chinese Wanfang Data Knowledge Service Platform, Chinese National Knowledge Infrastructure and Chinese Biology Medicine were searched up to February 2017. A total of 20 case-control studies including 2113 esophageal cancer cases and 2848 relevant controls were screened out. Overall, the meta-analysis demonstrated significant associations between the GSTM1 null genotype and increased risk for esophageal cancer in the Chinese population. In subgroup analyses, it indicated the similar results in population-based and hospital-based studies, as well as in North China and South China. As for subgroup analysis by histological type, a non-significant association was found in esophageal squamous cell carcinoma. Our study suggested that GSTM1 null genotype might contribute to increased risk of esophageal cancer in Chinese population.

Overall Survival of Patients with Locally Advanced or Metastatic Esophageal Squamous Cell Carcinoma Treated with Nimotuzumab in the Real World

INTRODUCTION

Despite improvements in surgical techniques and treatments introduced into clinical practice, the overall survival of patients with esophageal squamous cell carcinoma remains low. Several epidermal growth factor receptor inhibitors are being evaluated in the context of clinical trials, but there is little evidence of effectiveness in real-world conditions. This study aimed at assessing the effectiveness of nimotuzumab combined with onco-specific treatment in Cuban real-life patients with locally advanced or metastatic esophageal squamous cell carcinoma.

METHODS

A comparative and retrospective effectiveness study was performed. The 93 patients treated with nimotuzumab were matched, with use of propensity score matching, with patients who received a diagnosis of locally advanced or metastatic squamous cell carcinoma of the esophagus in three Cuban provinces reported between 2011 and 2015 to the National Cancer Registry. The Kaplan-Meier method was used to estimate event-time distributions. Log-rank statistics were used for comparisons of overall survival between groups. A two-component mixture model assuming a Weibull distribution was fitted to assess the effect of nimotuzumab on short-term and long-term survival populations.

RESULTS

There was an increase in median overall survival in patients treated with nimotuzumab (11.9 months versus 6.5 months without treatment) and an increase in the 1-year survival rate (54.0% versus 21.9% without treatment). The 2-year survival rates were 21.1% for patients treated with nimotuzumab and 0% in the untreated cohort. There were statistically significant differences in survival between groups treated and not treated with nimotuzumab, both in the short-term survival population (6.0 months vs 4.0 months, p = 0.009) and in the long-term survival population (18.0 months vs 11.0 months, p = 0.001).

CONCLUSIONS

Our study shows that nimotuzumab treatment concurrent with chemoradiotherapy increases the survival of real-world patients with locally advanced or metastatic esophageal squamous cell carcinoma. Further prospective studies are required to confirm the therapeutic effectiveness of nimotuzumab in esophageal cancer.

Nimotuzumab Combined with Chemotherapy is a Promising Treatment for Locally Advanced and Metastatic Esophageal Cancer

Background

Nimotuzumab is an anti-EGFR monoclonal antibody which has been widely used in cancer treatment. However, the safety and efficacy of nimotuzumab combined with chemotherapy in locally advanced or metastatic esophageal cancer patients remain unclear.

Material/Methods

To address this open question, we collected a total data of 21 patients diagnosed with locally advanced or metastatic esophageal cancer between 2012 and 2016 in a, retrospective study. The patient characteristics, efficacy safety, and toxicity were evaluated in our study.

Results

We observed 1 (4.8%) patient with complete response, 7 (33.3%) patients with partial response, 9 (42.9%) patients with stable response and 4 (19%) patients with progression response. The objective response rate was 38.1% and disease control rate was 81%. The mean progression-free-survival was 7 months and the 18-month overall survival (OS) was 10%. The incidence rate of anemia and leukopenia was 71.4% and 81%, respectively. Two patients showed the serious adverse event of myelosuppression, with nausea, fatigue, and anorexia. No long-term drug-related toxicity was observed during the follow-up.

Conclusions

Nimotuzumab combined with chemotherapy can achieve promising clinical outcomes in locally advanced or metastatic esophageal cancer, without accumulation of toxicity and was well-tolerated.

Targeted therapy in esophageal cancer

An increasing number of patients are diagnosed with esophageal cancer at an advanced stages, and only a small group of them can benefit from the traditional chemotherapy and radiotherapy. So far, multiple monoclonal antibodies and tyrosine kinase inhibitors have been developed, alone or in combination with traditional therapy, to improve the prognosis of patients with advanced esophageal cancer. This review summarizes the recent advances of targeted therapies against EGFR, HER2, VEGFR and c-MET in esophageal cancer. More clinical trials should be performed to evaluate the efficacy and safety of various targeted therapy regimens. Future basic research should focus on investigating the molecular mechanisms of therapeutic targets in esophageal cancer.

Nanoparticles for radiooncology: Mission, vision, challenges

Cancer is one of the leading non-communicable diseases with highest mortality rates worldwide. About half of all cancer patients receive radiation treatment in the course of their disease. However, treatment outcome and curative potential of radiotherapy is often impeded by genetically and/or environmentally driven mechanisms of tumor radioresistance and normal tissue radiotoxicity. While nanomedicine-based tools for imaging, dosimetry and treatment are potential keys to the improvement of therapeutic efficacy and reducing side effects, radiotherapy is an established technique to eradicate the tumor cells. In order to progress the introduction of nanoparticles in radiooncology, due to the highly interdisciplinary nature, expertise in chemistry, radiobiology and translational research is needed. In this report recent insights and promising policies to design nanotechnology-based therapeutics for tumor radiosensitization will be discussed. An attempt is made to cover the entire field from preclinical development to clinical studies. Hence, this report illustrates (1) the radio- and tumor-biological rationales for combining nanostructures with radiotherapy, (2) tumor-site targeting strategies and mechanisms of cellular uptake, (3) biological response hypotheses for new nanomaterials of interest, and (4) challenges to translate the research findings into clinical trials.

Coexpression of periostin and EGFR in patients with esophageal squamous cell carcinoma and their prognostic significance

Background

Both periostin (PN) and epidermal growth factor receptor (EGFR) can predict the prognosis of several carcinomas alone. However, coexpression of PN and EGFR in esophageal squamous cell carcinoma (ESCC) still remains unknown. We aimed to clarify their relationship with clinicopathological factors and prognostic significance of their coexpression in ESCC.

Patients and methods

In this single-center retrospective study, immunohistochemistry was performed to evaluate the expression of PN and EGFR in ESCC and paracarcinomatous tissues of 83 patients. The quantitative expression levels of PN and EGFR were examined in two ESCC and tumor-adjacent tissues. The levels of PN and EGFR expression were correlated with clinicopathological parameters by the χ² or Kruskal–Wallis method. Spearman’s rank correlation test was performed to determine the relationship between PN and EGFR expression levels. Kaplan–Meier and Cox regression analyses were used to detect the prognostic factors of disease-free survival (DFS) and overall survival (OS).

Results

The high expression of PN protein in ESCC tissues was significantly associated with tumor length (P=0.044), differentiation grade (P=0.003), venous invasion (P=0.010), invasion depth (P=0.007), lymphatic metastasis (P=0.000), and tumor stage (P=0.000). The high expression of EGFR protein in ESCC tissues was only significantly related to lymphatic metastasis (P=0.000), invasion depth (P=0.022), and tumor stage (P=0.000). Kaplan–Meier analysis showed that high expression of PN was closely correlated to reduced OS (P=0.000) and DFS (P=0.000), which was consistent with EGFR expression. Cox regression analysis identified PN and EGFR as independent poor prognostic factors of OS and DFS in the ESCC patients (P<0.05). Moreover, the risk of death for the ESCC patients with low expression of two biomarkers and high expression of single biomarker was 0.243 times (P=0.000) and 0.503 times (P=0.030), respectively, than that for patients with high expression of two biomarkers.

Conclusion

PN and EGFR are related to miscellaneous clinicopathologic characteristics. Coexpression of PN and EGFR is more closely to be of predictive value on ESCC development and progression, which may offer a novel and potential target strategy for ESCC treatment in the future.

High EGFR and low p-Akt expression is associated with better outcome after nimotuzumab-containing treatment in esophageal cancer patients: preliminary clinical result and testable hypothesis

The epidermal growth factor receptor (EGFR) is widely overexpressed in esophageal squamous cell carcinoma (ESCC) and it results is associated with a poor prognosis. Identifying the subgroup of ESCC patients who are sensitive to EGFR-targeted therapy is a key point to facilitate its medical use.

We retrospectively analyzed 32 ESCC patients treated with the combination of nimotuzumab (h-R3) and radiotherapy (RT) or chemoradiotherapy (CRT). Expression of EGFR and phosphorylated proteins associated with EGFR signaling pathway, i.e. p-Akt and p-Erk, were assessed with immunohistochemistry (IHC) for all patients. Correlations between these proteins' expression levels and overall survival (OS) were assessed.

High expression of EGFR, p-Akt and p-Erk was detected in 53.1% (17/32), 54.8% (17/31) and 59.4% (19/32) of tumors respectively. No significant differences in OS were found between high EGFR, p-Akt and p-Erk expression groups and their respective counterparts. Of note, significantly better overall survival was observed in patients with coexistence of high EGFR expression and low p-Akt expression (p = 0.030).

Our data allowed us to put forward a hypothesis that high EGFR and low p-Akt expression may predict a clinical benefit of EGFR antagonists such as nimotuzumab combined with RT or CRT. This can be discussed in the terms of oncogene addiction and synthetic lethality concepts. This hypothesis can be further tested in larger groups of patients.

High-dose nimotuzumab improves the survival rate of esophageal cancer patients who underwent radiotherapy

Nimotuzumab (h-R3) is a humanized monoclonal antibody that is safe to use against epidermal growth factor receptor (EGFR). However, the available information is insufficient about the dose effect of monoclonal antibody against epidermal growth factor receptor for the treatment of esophageal squamous cell carcinoma (ESCC). We retrospectively recruited 66 patients with ESCC who were treated with h-R3 and chemoradiotherapy/radiotherapy. Patients who received more than 1,200 mg of h-R3 were classified as the high-dose group, and the remaining patients were classified as the low-dose group. The endpoint for efficacy was the overall survival. Differences in survival between the groups were analyzed using the log-rank test. The Cox proportional hazards model was used in multivariate analysis to identify independent prognostic factors. The low-dose and high-dose groups comprised 55 and eleven patients, respectively. The median follow-up time in the final analysis was 46 months. The high-dose group showed no increased incidence of toxicities compared to the low-dose group. The 1-, 2-, and 5-year overall survival rates in the low-dose and high-dose groups were 66.9%, 50.0%, 31.5% and 90.0%, 80.0%, 66.7%, respectively (P=0.04). Multivariate analyses showed that the high-dose group had better survival than the low-dose group (hazard ratio 0.28, 95% confidence interval 0.09–0.94, P=0.039). Taken together, high-dose h-R3 showed limited toxicity and improved survival in patients with ESCC.

The relation of EGFR expression by immunohistochemical staining and clinical response of combination treatment of nimotuzumab and chemotherapy in esophageal squamous cell carcinoma

INTRODUCTION

The esophageal squamous cell carcinoma (ESCC) is the predominant pathological type and accounts for more than 80 % of esophageal cancer in China. The successful use of anti-epidermal growth factor receptor (EGFR) treatment in head and neck squamous cell carcinoma provides the rationale for introducing anti-EGFR targeting treatment in ESCC. One of our prospective phase II clinical trials analyzed the efficacy of nimotuzumab, an anti-EGFR agent, combined with chemotherapy (paclitaxel and cisplatin) to treat unresectable ESCC.

MATERIALS AND METHODS

We analyzed the correlation of the clinical response with EGFR expression by immunohistochemical staining (IHC).

RESULTS

Totally 55 tumor samples were analyzed. 18/55 (32.7 %) cases were with high EGFR expression while the other 37/55 (67.3 %) cases were with low to moderate EGFR expression. The expression of EGFR was not related to gender, age, tumor location, tumor differentiation and clinical stage of disease. The objective response rate (ORR) in high EGFR expression group was 55.6 % (10/18) while that in low to moderate EGFR expression group was 54.1 % (20/37) (P = 0.57). Both the progression-free survival (PFS) and overall survival (OS) in high EGFR expression group were much shorter than those in low to moderate EGFR expression group (PFS: 5.8 ± 0.5 vs. 11.0 ± 2.8 months, P = 0.007; OS: 9.7 ± 0.5 vs. 21.5 ± 1.5 months, P = 0.03).

CONCLUSIONS

The results showed that over-expression of EGFR was related to poor survival of ESCC. The over-expression of EGFR by IHC might not be an ideal predictive biomarker of nimotuzumab treatment. Other EGFR pathway-associated molecules should be analyzed in further studies.

Efficacy and toxicity of nimotuzumab combined with radiotherapy in elderly patients with esophageal squamous cell carcinoma

This study was conducted to assess the efficacy and toxicity of nimotuzumab combined with radiotherapy (RT) in elderly patients with esophageal squamous cell carcinoma. The clinical data of 16 esophageal squamous cell carcinoma patients, aged >70 years, who were initially treated with nimotuzumab combined with RT, were collected and retrospectively reviewed. The overall response and treatment toxicity were analyzed using SPSS software. All the patients completed the treatment schedule. The response to treatment was assessed at treatment completion and reassessed after 1-2 months: 1 patient achieved complete response (CR), 10 patients achieved partial response (PR), 4 patients exhibited stable disease and 1 patient developed disease progression and succumbed to radiation pneumonitis (RP) 1 month later. The overall response rate (CR+PR) was 68.8%. All 16 patients experienced grade 1-2 radiation esophagitis; no grade 3-4 toxicities were reported. There was one case of treatment-related mortality due to RP during the study. One patient developed a rash on the forearm. No hematological, gastrointestinal, hepatic or renal toxicities were observed. In conclusion, the toxicity of combined nimotuzumab with RT in elderly patients with esophageal cancer was tolerable. However, due to limitations associated with the retrospective nature of this study, the limited number of enrolled cases and the epidermal growth factor receptor expression determination prior to treatment, the efficacy of this treatment modality requires further investigation.

Nimotuzumab enhances radiation sensitivity of NSCLC H292 cells in vitro by blocking epidermal growth factor receptor nuclear translocation and inhibiting radiation-induced DNA damage repair

Background

The epidermal growth factor receptor (EGFR) signaling pathway plays a significant role in radiation resistance. There is evidence that EGFR nuclear translocation is associated with DNA double-strand breaks (DSB) repair. Nimotuzumab has shown the effect of radiosensitization in various cancer cells, but little is known about the relationship between nimotuzumab and EGFR nuclear translocation in non-small cell lung cancer (NSCLC) cell lines. In this study, we selected two NSCLC cell lines, namely, H292 (with high EGFR expression) and H1975 (with low EGFR expression) and explored the mechanisms underlying radiation sensitivity.

Methods

MTT assay, clonogenic survival assay, and flow cytometry were performed separately to test cell viability, radiation sensitivity, cell cycle distribution, and apoptosis. Protein γ-H2AX, DNA-PK/p-DNA-PK, and EGFR/p-EGFR expression were further compared both in the cytoplasm and the nucleus with the western blot.

Results

Nimotuzumab reduced the viability of H292 cells and sensitized H292 cells to ionizing radiation. The radiation sensitivity enhancement ratio (SER) was 1.304 and 1.092 for H292 and H1975 cells, respectively. H292 cells after nimotuzumab administration were arrested at the G0/G1 phase in response to radiation. Apoptosis was without statistical significance in both cell lines. γ-H2AX formation in the combination group (nimotuzumab and radiation) increased both in the cytoplasm and the nucleus along with the decreased expression of nuclear EGFR/p-EGFR and p-DNA-PK in H292 cells (P<0.05) that was more significant than that in H1975 cells.

Conclusion

Our research revealed a possible mechanism to explain the radiosensitivity in H292 cells. Nimotuzumab decreased the radiation-induced activation of DNA-PK by blocking EGFR nuclear translocation and impairing DNA DSB repair, thus enhancing radiosensitivity in H292 cells. Because these results represent early research, the matters of how γ-H2AX and DNA-PK dynamically change simultaneously with nuclear EGFR and the best time to administer nimotuzumab will require further exploration.

[Nimotuzumab significantly enhances chemosensitivity of PC9 human lung adenocarcinoma cells to paclitaxel in vitro]

BACKGROUND

Nimotuzumab is a humanized IgG1 type monoclonal antibody targeting epidermal growth factor receptor, and can enhance chemosensitivity and radiosensitivity of certain cancers. The aim of this study is to investigate the effects of nimotuzumab on the chemosensitivities of PC9 human lung adenocarcinoma cells to common chemtherapeutic drugs including ciaplatin, gemcitabine, paclitaxel, pemetrexed and vinorelbine, and to elucidate possible mechanisms.

METHODS

PC9 human lung adenocarcinoma cell line was used in the study. Cell proliferation was determined by WST-1 assay and cell apoptosis was detected by TUNEL assay. Cell cycle distribution was analyzed by DNA analysis with FACS. Tublin and microfilaments were observed by immunofluorescence staining.

RESULTS

Nimotuzumab significantly enhanced the chemosensitivity of PC9 cells to paclitaxel. Cell proliferation was inhibited significantly (P<0.05) and cell apoptosis rate was higher in nimotuzumab combined with low dose paclitaxel (0.05 μg/mL) group (P=0.013). G2/M arrest was increased significantly by nimotuzumab combined with paclitaxel group (P<0.05). Nimotuzumab caused aggregation of tublin and microfilaments into well organized microtubules.

CONCLUSIONS

Nimotuzumab enhanced the chemosensitivity of PC9 cell to paclitaxel by enhancing G2/M arrest and aggregation of tublin and microfilaments. Therefore, Nimotuzumab combined with taxane drugs could be a potential effective regimen in non-small cell lung cancer.

From conventional chemotherapy to targeted therapy: use of monoclonal antibodies (moAbs) in gastrointestinal (GI) tumors

In recent years, significant progress has been made in the diagnosis and treatment of gastrointestinal cancers. Researches and clinicians however are still faced with challenges, not the least is the detection and management of tumors with varied gene mutation status. Clarification of the molecular pathology of gastrointestinal cancers may improve treatment options as well as quality of life and the long-term survival of this patient class. Therefore, molecular-targeted therapies have emerged as clinically useful drugs for gastrointestinal cancers cure, and predictive biomarkers have been heralded as the way to develop the right drug for the right patient. Moving from such appealing molecular background, we wrote an overview of the main targeted therapies, with particular interest to monoclonal antibodies that have already been approved in clinical practice or are being tested in gastrointestinal cancers treatment.

Investigational therapies targeting the ErbB family in oesophagogastric cancer

INTRODUCTION

The prognosis for patients with oesophagogastric (OG) cancer remains poor, with a median survival of approximately 9 - 11 months for patients with metastatic disease. However, a more personalised approach to treatment, using drugs tailored to the molecular characteristics of patients' tumours, has the potential to improve patient outcomes. Drugs targeting the ErbB family of receptors have been developed, but these have had varying degrees of success in clinical practice.

AREAS COVERED

The authors provide an overview of the ErbB receptor family with regard to OG cancers. Furthermore, they evaluate the evidence from preclinical and clinical trials of therapeutics targeting this family, including monoclonal antibodies, tyrosine kinase inhibitors and novel agents.

EXPERT OPINION

Drugs targeting the ErbB family have been evaluated in OG cancer, with a notable success story in the case of trastuzumab, although there have been disappointing failures with anti-EGFR therapy. The response to targeted treatment remains variable and further biomarker research is essential to identify patients most likely to benefit from these therapies. The treatment of OG cancer remains challenging, but new anti-HER2 therapies and combination therapies hold promise for the future.

Anti-tumor effect of integrin targeted (177)Lu-3PRGD2 and combined therapy with Endostar

PURPOSE

Targeted radiotherapy (TRT) is an emerging approach for tumor treatment. Previously, 3PRGD2 (a dimeric RGD peptide with 3 PEG4 linkers) has been demonstrated to be of advantage for integrin αvβ3 targeting. Given the promising results of (99m)Tc-3PRGD2 for lung cancer detection in human beings, we are encouraged to investigate the radiotherapeutic efficacy of radiolabeled 3PRGD2. The goal of this study was to investigate and optimize the integrin αvβ3 mediated therapeutic effect of (177)Lu-3PRGD2 in the animal model.

EXPERIMENTAL DESIGN

Biodistribution, gamma imaging and maximum tolerated dose (MTD) studies of (177)Lu-3PRGD2 were performed. The targeted radiotherapy (TRT) with single dose and repeated doses as well as the combined therapy of TRT and the anti-angiogenic therapy (AAT) with Endostar were conducted in U87MG tumor model. The hematoxylin and eosin (H&E) staining and immunochemistry (IHC) were performed post-treatment to evaluate the therapeutic effect.

RESULTS

The U87MG tumor uptake of (177)Lu-3PRGD2 was relatively high (6.03 ± 0.65 %ID/g, 4.62 ± 1.44 %ID/g, 3.55 ± 1.08 %ID/g, and 1.22 ± 0.18 %ID/g at 1 h, 4 h, 24 h, and 72 h postinjection, respectively), and the gamma imaging could visualize the tumors clearly. The MTD of (177)Lu-3PRGD2 in nude mice (>111 MBq) was twice to that of (90)Y-3PRGD2 (55.5 MBq). U87MG tumor growth was significantly delayed by (177)Lu-3PRGD2 TRT. Significantly increased anti-tumor effects were observed in the two doses or combined treatment groups.

CONCLUSION

The two-dose TRT and combined therapy with Endostar potently enhanced the tumor growth inhibition, but the former does not need to inject daily for weeks, avoiding a lot of unnecessary inconvenience and suffering for patients, which could potentially be rapidly translated into clinical practice in the future.